Transit concrete mixer



June 10, 1930. j MQRRIS 1,763,249

TRANS IT CONCRETE MIXER Filed Jan. 22, 1929 2 Sheets-Sheet 1 lNVEN T0/ Joseph E. M WfI A TTORNE June 10, 193 0. J MORRIS 1,763,249

TRANS IT CONCRETE MIXER Filed Jan. 22; 1929 2 Sheets-She et 2 INVENTOR Jogep? 8.9102 2%;

4 ATTORNEY Patented June re. 1936? unrra s'rrss mam TENT orr ics aosnrn n. monnrs, or s nATrLn, wasnrneron, nssrenon or own-rooms: 'ro

cnannncn M. TUCK, or snnrrnn, WA$EINGTGN TRANSIT CONCRETE MIXER Application filed .lanuary 22, 1929. Serial No 334,189

My invention refers to the art of concrete mixers and more particularly to that type of mixer which, because of its features which I believe to be new, lends itself to mounting on a truck and thus becomes what is more commonly termed a transit concrete mixer. the various types of transit concrete mixers now in use, it has been found necessary either to make a very complicated mechanism that will accomplish the two-fold purpose of mixing and discharging, or so construct the ma chine that it will only mix and then supplying an additional hoisting mechanism to elevate one end of the mixing chamber and thus discharge the mixed concrete.

The principal object of my invention, therefore, is to provide a concrete mixer of very simple construction, which will thoroughly mix the aggregate and discharge the same 2 without the need of any hoisting equipment.

A further object of my invention is to provide a mixing chamber, using fiat sides instead of the conventional type which uses a round cylinder and separate baffles which are secured therein.

A further object is to use a portion of the chamber spacethat would normally be waste for the purpose of storing the water necessary to wet the aggregate and thus produce to concrete.

A further object is to provide a mixer that is capable of mixing satisfactorily even though it is practically full of aggregate.

The above general objects of my invention together with others inherent in the same are obtained by the device illustrated in the following drawing, the same being a pre fcrrcd form of embodiment of my invention, throughout which drawings like reference numerals indicate like parts.

Figure 1 is a longitudinal vertical section through my invention.

Figure 2 is a transverse section substantially along the line 22 of figure 1.

Figure 3 is. an end elevation looking from the rear end.

Figure 4 is an enlarged cross section taken in the same plane as Figure 1, showing the bearing and stufling box. in enlarged detail. Referring to the drawings numeral 6 indicates in general the mixing chamber, which is shown in Figure-2 as square in cross section. However any number of flat sides Ina be used. For simplicity of construction normally prefer the four sides, however. I

have also shown the length to be approximately equal to the length of one side of the 1 square. This is a desirable relationshipbut need not be used exactly. A flat plate 8-is secured usually by electric welding in one corner of the square in a manner as shown in Figures 1 and 2. The purpose of this plate is to provide asloping surface which will cause the concrete to flow out the spout 9 which is normally closed by the cover and to further provide the water storage tank 13. The mixing chamber 6 is preferably mounted on a shaft 15 passing entirely through the chamber and having thereon the bearings 18 in which the shaft is free to turn. The shaft 15 is secured and supported by the bearing members 20 and 22, which I have shown in Figure 3 to be of the common A frame construction. A. large driven gear 25 is secured to the mixing chamber concentricwith the shaft 15 and is in turn driven by the pinion 27. Pinion 27 is secured to an intermediate shaft 28 which is journaled in the bearing 30, which in turn is supported by the front A frame member 22. Any convenient driving means may be employed to drive shaft 28.

l have shown the sprockets 33 and 34 with a chain 36 engaging the same. Sprocket 34: is preferably driven by a power take-off 40, which maybe of any standard construction; the one I have found quite satisfactory is the type in which the drive line is interrupted, while the power is taken therefrom. In this construction it is impossible to turn the propeller shaft 43 and the mixer at the same time. This has the inherent fault of not permitting the machine revolving while the truck is in motion but I have found that usually the motive power of the truck is not sufiicient to both propel the vehicle and operate the mixer at the same time. I would not care to limit myself, however. to this construction, as I have found that in certain cases, particularly in level country, it is often desirable to actually mix the aggregate while the truck is in motion and were these conditions present, 1 would use a power-take-olf that would permit this operation.

Referring to Figures 1 and 2 I have shown a series of blades 50 which are of such a length that they will clear the plate 8 by an amount slightly greater than the maximum dimension of any gravel to be handled. The blades 50 are set at an angle such that the material in being carried past them will be moved towards the front of the mixer. This will leave a layer of material usually about three or four inches thick that will be free to flow down the incline provided by plate 8 and in this manner an end to end circulation of material is achieved which will produce a very thorough mixing of the aggregate which is normally sand, gravel and cement. Plate 8, as the chamber is revolved, displaces material to the rear when near the position shown in Figure 1 and toward the front when not near the position shown. It will be understood, I believe, that blades 50 are rigidly secured to shaft 15, which shaft is itself locked against rotation.

Referring to Figure 4 I show a detail which might be either of the bearings 18. Bearing 18 I prefer to line with some bearing material such as Babbitt or bronze, as indicated by 56. Rings of hydraulic packing 58 are pressed tightly against the shaft 15 by the stuffing box 59. I have found, however, that as the drum turns about the fixed shaft 15 the Very finely ground particles of cement tend-to work their way through the packing along the shaft and to take care of this I provide a discharge or weep hole 61. I have further found as a convenience in assembling and repairing my machine that it is desirable to cut a hole 62 in the end walls 65 of the drum 6, which will be sufficiently large to permit the withdrawal of the stuffing box 59. I prefer to take the cutout section 67 and use it as a spacer so that the securing bolts which hold the stuffing box 59 to the bearing 18 will also pass through plate 67. Bearing 18 is securely bolted to the end plate 65 and thus prevents any leakage at this point.

Method of operation In operating my device the proper proportions of aggregate usually sand, cement and gravel, are placed in the mixing chamber 6, at a central bunker or storage place. The proper amount of water to thoroughly Wet this aggregate is then placed in the water tank 13. I have found it convenient to charge the mixer by having the spout 9 uppermost and using a chute or spout to deposit the material in the mixing chamber.

If the nature of the ground will permit the mixer may be started at a point not far from the point of discharging and the materials thus mixed dry. As soon as the job has been reached, the water valve 70 is opened with the water tank 13 in the uppermost position and all the water allowed to drain into the mixing chamber. The valve is then closed and the drum revolved until a thorough mixture is secured. lVhen it is desired to discharge -the concrete, the drum is stopped with the discharge spout 9 at the lowest position, such as indicated in Figure 1. As soon as the door 11 is released and opened, the concrete which is now fluid, will flow down the incline 8 and be discharged.

What I claim is:

1. In a transit concrete mixer, a prismatic mixing chamber, a fixed shaft adapted to journal said mixing chamber, propelling blades secured to said fixed shaft, a discharge chute formed by extending the adj acent sides at one corner, a sloping plate secured in one corner of the mixing chamber so as to form a rearward discharging slope and drive means for the mixing chamber.

2. In a transit concrete mixer, a prismatic mixing chamber, a fixed shaft adapted to journal said mixing chamber, propelling blades secured to said fixed shaft, a dis charge chute formed by extending the adjacent sides at one corner, a sloping plate secured in one corner of the mixing chamber so as to form a rearward discharging slope, a water tank, disposed in the chamber formed by the sloping plate and drive means for the mixing chamber.

3. In a transit concrete mixer, a prismatic mixing chamber, a fixed shaft adapted to journal said mixing chamber, propelling blades secured to said fixed shaft, a discharge chute formed by extending the adjacent sides at one corner, a sloping late secured in one corner of the mixing 0 amber so as to form a rearward discharging slope, a water tank, disposed in the chamber formedby the sloping plate, stuffing boxes encircling the shaft at its points of entrance into the mixing chamber and drive means for the mixing chamber.

4. In a transit concrete mixer, a prismatic mixing chamber, a fixed shaft adapted to journal said mixing chamber, propelling blades secured to said fixed shaft, a discharge chute formed at one corner, a sloping plate secured in one corner of the mixing chamber so as to form a rearward discharging slope and drive means for the mixing chamher.

5. In a transit concrete mixer, a prismatic mixing chamber, a fixed shaft adapted, to journal said mixing chamber, propelling blades secured to said fixed shaft, a discharge chute formed at one corner, a sloping plate secured in one corner of the mixing chamber so as to form a rearward discharging slope, a water tank, disposed in the chamber formed by the sloping plate and drive means for the mixing chamber.

6. In a transit concrete mixer, a prismatic mixing chamber, a fixed shaft adapted to journal said mixin chamber, propelling blades secured to said edshaft, a discharge chute formed at one corner, a sloping plate se-' cured in one corner of the mixing chamber so as to form a rearward discharging slope, a water tank, disposed in the chamber formed by the sloping plate, stuffing boxes encircling the shaft at its points of entrance into the mixing chamber and drive means for the mix ing chamber.

In witness whereof, I hereunto subscribe my name this 17th day of January A. D.

JOSEPH E. MORRIS. 

